The former mayor of New York made the bizarre statement as he explained his concerns over pushing the US president into an interview that he says could be a perjury trap.

Mr Giuliani used the line during an interview on NBC’s Meet the Press with Chuck Todd on Sunday.

He was trying to make the case that having Mr Trump sit down for an interview with the team investigating Russia’s role in the 2016 election would not accomplish much because of the “he-said-she-said” nature of witnesses’ recollections.

Mr Giuliani cited former FBI director James Comey as an example, who has said that Mr Trump pushed him at a private meeting to ease up in the federal investigation of former White House national security adviser Michael Flynn. Mr Trump has disputed his claims.

“I am not going to be rushed into having him testify so that he gets trapped into perjury,” Mr Giuliani said.

"Truth isn't Truth" – It is as if Rudy Giuliani revels in writing the book titles for the historians of the future who will have to try to make sense of this President and all that is transpiring under his Administration.

He added: “Donald Trump says, ‘I didn’t talk about Flynn with Comey’. Comey says, ‘You did talk about it’, so tell me what the truth is.”

Mr Todd was left flummoxed by the comments, putting his hand on his head and saying: “This is going to become a bad meme!”

Truth exists and truth matters. Truth has always been the touchstone of our country’s justice system and political life. People who lie are held accountable. If we are untethered to truth, our justice system cannot function and a society based on the rule of law dissolves.